At a glance Plusses: Lightweight, breathable, suited for light and fast trips Minuses: Slim fit may not suit everybodyFeatures: Constructed from two-layer Gore-Tex Paclite, the Knife Edge is fractionally heavier than a specialised running jacket (but it's still light - 326g -m; 303g -w). Like most modern rainwear, the Knife Edge is fully seam-sealed, including along its zippers. The pockets have remained dry through heavy rain, and I haven’t experienced any unpleasant leaks through the underarm pit-zips. The jacket’s hood is big enough to fit over a helmet but still manages to feel snug without a helmet on. It has a peripheral and rear drawcord to cinch it tight so that it moves with your head. A hem drawcord also comes in handy to minimise heat loss. The cuffs are cut asymmetrically, so the sleeve is longer on the outside of the arm. This provides good cover for hands without compromising dexterity. Fit: The jacket has an athletic cut and the sizing seems about average, with good arm and torso length, but there isn’t much room for a paunch. It’s a snug fit for me with three layers on, though the arm movement remains unrestricted. Comfort: Comfort has much to do with fit, and the Knife Edge fits me well. The athletic cut helps to retain heat in cool conditions, and also ensures water doesn’t pond. The lightweight two-layer construction and underarm ventilation make it impressively breathable, which helps to keep moisture levels under control during strenuous climbs or in wet conditions. In use: After a month of testing, the Knife Edge has been on several trips and has borne the brunt of some autumnal downpours. It has performed well in these and other conditions, from hill running to overnight tramping. Its weight and ‘packability’ make it a good option for those looking for a jacket to cover most conditions, from city life to the hills, without the usual bulk. 5/5 Value: Price-wise, the Knife Edge is in the middle of the pack. It sits squarely between heavier duty three-layer rain jackets and ultra-light running jackets. For expensive items like rain jackets, the real clincher is durability. Unfortunately, I have not had the jacket long enough to say how well it stands up in the long run but after a month of regular use, it shows no sign of wear. 4/5 Verdict: Trying to make outdoor clothing that is stylish enough to crossover into town-wear is a common pitfall that outdoor brands fall into as they try to expand their markets, but Marmot has pulled it off with the Knife Edge. The two-layer outer makes it light enough to wear on a run but hardy enough to take tramping and it has stood up well under torrential rain.